A new three-dimensional Zn(2+) coordination polymer constructed from oxalate and 1,2,4-triazolate.

A new 3-D Zn(2+) coordination polymer (CP) [(CH3)2NH2]3[Zn6(ox)4.5(trz)6]⋅4H2O (ox=oxalate; trz=1,2,4-triazolate) 1 was obtained by a simple solvothermal self-assembly. The crystal structural analysis demonstrates that the trz molecules link the Zn(2+) ions into a two-dimensional (2-D) layer network, which is based on the trinuclear Zn3(trz)6 clusters. The ox molecules serve as the linkers to propagate the 2-D layers into a three-dimensional (3-D) network of 1. The thermogravimetry (TG) behavior, photoluminescence property, and the sensing ability of 1 are investigated. The sensing experiment on nitrobenzene (NB) reveals that 1 can serve as a fluorescence probe to detect NB at the ppm concentration.

One-pot synthesis of antibacterial monomers with dual biocidal modes.

OBJECTIVES: The present study reported a method for preparing a blend of antibacterial quaternary ammonium silanes and quaternary ammonium methacryloxy silane (QAMS) based on the sol-gel reaction between dimethyldiethoxy silane and two trialkoxysilanes, one with an antibacterial quaternary ammonium functionality and the other with a methacryloxy functionality. METHODS: Reaction products of the sol-gel reaction were characterised by direct infusion mass spectrometry, FTIR and proton, carbon and silicon NMR. This blend of monomers was incorporated into an experimental universal adhesive for evaluation of antimicrobial activity against Streptococcus mutans biofilms, microtensile bond strength and cytotoxicty. Retention of quaternary ammonium species on polymerised adhesive, leaching of these species from the adhesive and the ability of resin-dentine interfaces to inhibit S. mutans biofilms were evaluated over a 3-month water-ageing period. RESULTS: The antibacterial adhesive version killed bacteria in S. mutans biofilms not only through the release of non-copolymerisable quaternary ammonium silane species (release-killing), but also via immobilised quaternary ammonium methacryloxy silane that are copolymerised with adhesive resin comonomers (contact-killing). Contact-killing was retained after water-ageing. The QAMS-containing universal adhesive has similar tensile bond strength as the control and two commercially available universal adhesives, when it was used for bonding to dentine in the etch-and-rinse mode and self-etching mode. Incorporation of the antimicrobial quaternary ammonium species blend did not adversely affect the cytotoxicity of the universal adhesive formulation. CONCLUSIONS: Instead of using quaternary ammonium dimethacrylates and nanosilver, an alternative bimodal antimicrobial strategy for formulating antimicrobial universal dentine adhesives is achieved using the one-pot sol-gel synthesis scheme. CLINICAL SIGNIFICANCE: The QAMS containing universal dentine adhesives with dual antimicrobial activity is a promising material aimed at preventing second caries and prolonging the longevity of resin composite restorations.

Anatomy of sodium hypochlorite accidents involving facial ecchymosis - a review.

OBJECTIVES: Root canal treatment forms an essential part of general dental practice. Sodium hypochlorite (NaOCl) is the most commonly used irrigant in endodontics due to its ability to dissolve organic soft tissues in the root canal system and its action as a potent antimicrobial agent. Although NaOCl accidents created by extrusion of the irrigant through root apices are relatively rare and are seldom life-threatening, they do create substantial morbidity when they occur. METHODS: To date, NaOCl accidents have only been published as isolated case reports. Although previous studies have attempted to summarise the symptoms involved in these case reports, there was no endeavour to analyse the distribution of soft tissue distribution in those reports. In this review, the anatomy of a classical NaOCl accident that involves facial swelling and ecchymosis is discussed. RESULTS: By summarising the facial manifestations presented in previous case reports, a novel hypothesis that involves intravenous infusion of extruded NaOCl into the facial vein via non-collapsible venous sinusoids within the cancellous bone is presented. CONCLUSIONS: Understanding the mechanism involved in precipitating a classic NaOCl accident will enable the profession to make the best decision regarding the choice of irrigant delivery techniques in root canal débridement, and for manufacturers to design and improve their irrigation systems to achieve maximum safety and efficient cleanliness of the root canal system.

Caries experience in individuals with cleft lip and/or palate in China.

OBJECTIVE: To determine the levels of dental caries in subjects with cleft lip and/or palate in China in comparison with controls. DESIGN: A total of 380 subjects with cleft lip and/or palate and 339 non cleft control subjects were examined for dental caries using the decayed-missing-filled-teeth (DMFT/dmft) and decayed-missing-filled-surfaces (DMFS/dmfs) index. A questionnaire was used to acquire subjects' living habits and family socioeconomic status. SETTING: West China Stomatology Hospital, Sichuan University. SUBJECTS: Individuals between 3 and 25 years of age. RESULTS: Caries prevalence and scores for dmft/DMFT and dmfs/DMFS were significantly higher in subjects with cleft palates when compared with the non cleft control group (p < .05), except 3- to 5-year-old children (p > .05). However, in the 3- to 5-year-old group, children with cleft lip and/or palate had significantly more caries than children of the same age with only a cleft lip with or without alveolus (p < .05). Children whose clefts had been surgically repaired had a lower dmft and dmfs than those whose clefts had not been surgically repaired (p < .05). CONCLUSION: Individuals with oral cleft are at an increased risk for dental caries. The types of cleft and the surgical repair are two important factors for dental caries.

[Determination of organic acids in dental plaque with high performance liquid chromatography].

OBJECTIVE: To establish determination method of formic acid, lactic acid, acetic acid and succinic acid in dental plaque with high performance liquid chromatography (HPLC). METHODS: After the samples were centrifuged, 2 microL supernatant was transferred to a 1 mL centrifuge tube and diluted in water, then was determined with HPLC. The mixture of phosphate buffer and methanol (97:3) as mobile phase throughout the experiment. The determination of organic acid was performed on Phenomenex C18 column and at their maximum absorption wave. RESULTS: The linear ranges of formic acid, lactic acid, acetic acid and succinic acid were 0.110-500, 0.049-500, 0.047-500, 0.084-500 microg/mL. The detection limits were 0.110, 0.049, 0.047, 0.084 microg/mL. The relative standard derivation were 9.5%, 7.9%, 4.3%, 4.2%. The average recoveries of samples were 82%-112%, 82%-102.5%, 90%-115%, 80%-110%. CONCLUSION: The method was simple, quick and adapt for analysis of organic acid in dental plaque.

[Dental caries in children with cleft lip and/or palate in China].

OBJECTIVE: To determine the prevalence of dental caries in children with cleft lip and Palate. METHODS: A cross-sectional study was undertaken in 380 children with cleft lip and Palate and 339 children without cleft. Dental caries were measured with decayed-missing-filed-teeth index (DMFT/dmft) and the decayed-missing-filed-surface index (DMFS/dmfs). A questionnaire survey about the socio-economic conditions and lifestyles of the children's families was undertaken in the parents of the children. RESULTS: (1) The children with cleft Palates had a higher prevalence of caries and greater DMFT(S) and dmft(s) scores than the children without cleft (P < 0.05), except for those of 3 to 5 years old. (2) For the children of 3 to 5 years old, those with cleft lip and palate had significantly more caries than those with only a cleft lip or a cleft lip and alveolus (P < 0.05). The children who had surgical repairs had lower dmft(s) than those who had not (P < 0.05). CONCLUSION: (2) Chinese children with oral cleft have more dental caries than the children without cleft. (2) Children with cleft lip and palate have higher levels of dental caries than those with cleft lip alone. The children who had surgical repairs have less dental caries.